Sodium salt of an azo derivative of 5-aminosalicylic acid

ABSTRACT

The present invention relates to the sodium salt of (Z)-2-hydroxy-5-([4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl ]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoic acid, as well as to the pharmaceutical compositions containing it, to a procedure for its preparation and to its use for the manufacture of medicaments for the treatment or prevention of inflammatory bowel disease.

FIELD OF THE INVENTION

The present invention relates to a new salt of an azo derivative of5-aminosalicylic acid, and more particularly to the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid. The present invention also relates to the pharmaceuticalcompositions containing it, to a procedure for its preparation and toits use for the manufacture of medicaments useful for the treatment orprevention of inflammatory bowel disease.

BACKGROUND OF THE INVENTION

Inflammatory bowel disease is a chronic inflammatory disease of theintestine, whose etiology is still unknown. The most prevalent forms ofthis disease are ulcerative colitis and Crohn's disease.

Patent application WO 97/09329 discloses a series of azo derivatives of5- aminosalicylic acid (5-ASA) that are useful for the treatment ofinflammatory bowel disease. These compounds combine in the same molecule5-ASA and a compound having PAF-antagonist activity through an azo bond,and are designed to be metabolized in the colon by the intestinalbacteria in a similar manner to that described for the referencecompound sulfasalazine, to deliver 5-ASA and the PAF antagonist. One ofthe compounds described in this patent application is(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid, which is known in the literature as UR-12746 and whose formula isshown below:

The authors of the present invention have found that the levels ofazoreduction observed with this compound are low when studies on themetabolization of said azo bond are carried out. Since this kind ofcompounds are precisely designed to be metabolized and deliver in thecolon 5ASA and the PAF antagonist, which are the active molecules, theproblem arises of finding compounds that are metabolized in the colon toa greater extent. This problem is solved with the new salt that is theobject of the present invention.

SUMMARY OF THE INVENTION

The present invention relates to the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid of formula I:

It has been found that the sodium salt of the invention (i.e. the sodiumsalt of UR-12746) can exist in different forms, in particular inamorphous or noncrystalline form and in crystalline form. It has furtherbeen found that the sodium salt of the invention exists in two differentcrystalline forms, designated polymorph I and polymorph II, depending onthe preparation conditions, as explained in greater detail below. Thepresent invention relates to the sodium salt of UR-12746 in any of itsforms.

The present invention also relates to a process for the preparation ofthe sodium salt of formula I.

The present invention further relates to a pharmaceutical compositionwhich comprises an effective amount of the sodium salt of formula I andone or more pharmaceutically acceptable excipients.

The present invention also relates to the use of the sodium salt offormula I for the manufacture of a medicament for the treatment orprevention of inflammatory bowel disease. Throughout the presentdescription, the term “inflammatory bowel disease” is to be understoodas comprising ulcerative colitis, Crohn's disease as well as any otherform of inflammatory bowel disease.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a representative infrared spectrum of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid in amorphous form.

FIG. 2 shows a representative X-ray powder diffractogram of the sodiumsalt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoic acid inamorphous form.

FIG. 3 shows a representative differential scanning calorimetry (DSC)diagram of polymorph I of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]-phenyl]azo]benzoicacid.

FIG. 4 shows a representative infrared spectrum of polymorph I of thesodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid.

FIG. 5 shows a representative X-ray powder diffractogram of polymorph Iof the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azolbenzoicacid.

FIG. 6 shows a representative infrared spectrum of polymorph II of thesodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid.

FIG. 7 shows a representative X-ray powder diffractogram of polymorph IIof the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid.

FIG. 8 shows a representative differential scanning calorimetry (DSC)diagram of polymorph II of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]-phenyl]azo]benzoicacid.

DESCRIPTION OF THE INVENTION

As mentioned above, the present invention relates to the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid, of formula I:

Throughout the present description, we will refer to the new sodium saltthat is the object of the invention as the sodium salt of(Z)-2-hydroxy-5-[[4-[3-(4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid, the sodium salt of formula I or the sodium salt of UR-12746,without distinction.

Surprisingly, the authors of the present invention have found that thesodium salt of formula I is metabolized in the colon to a much greaterextent than the corresponding acid compound described in the prior art,that is UR-12746. Therefore, the new salt that is the object of theinvention is a more suitable compound for the manufacture of medicamentsfor the treatment or prevention of inflammatory bowel disease.

As mentioned above, it has been found that the sodium salt of theinvention can exist in amorphous or non-crystalline form and incrystalline form, depending on the conditions under which it isobtained, as described in more detail below. The present inventionrelates to the sodium salt of UR-12746 in any of its forms.

In an embodiment of the invention, the sodium salt of formula I isprovided in amorphous form.

In another embodiment of the invention, the sodium salt of formula I isprovided in crystalline form.

In another embodiment, the invention provides the polymorph I of thesodium salt of formula I, which exhibits an X-ray powder diffractogram,obtained at λ=1.542 Å and using a radiation source of Cu Kα, comprisingpeaks at an angle 20 of 6.04, 6.38, 8.01, 8.54, 11.73, 13.18, 13.65,14.55, 14.97, 16.08, 16.90, 17.23, 19.10, 19.53, 20.15, 21.12, 21.86,22.48, 23.71 and 24.23°±0.2°.

In another embodiment, the polymorph I of the sodium salt of formula Ihas an X-ray powder diffractogram substantially in accordance with thatshown in FIG. 5.

In another embodiment, the polymorph I of the sodium salt of formula Ihas an infrared spectrum substantially in accordance with that shown inFIG. 4.

In another embodiment, the polymorph I of the sodium salt of formula Ihas an X-ray powder diffractogram substantially in accordance with thatshown in FIG. 5 and an infrared spectrum substantially in accordancewith that shown in FIG. 4.

In another embodiment, the invention provides polymorph II of the sodiumsalt of formula I, which exhibits an X-ray powder diffractogram,obtained at λ=1.542 Åand using a radiation source of Cu Kα, comprisingpeaks at an angle 20 of 6.07, 8.30, 8.82, 11.71, 12.52, 13.24, 15.72,17.77, 18.96, 19.67, 20.33, 20.84, 21.39, 21.71, 22.77, 22.97, 23.50,23.95 and 29.50°±0.2°.

In another embodiment, the polymorph II of the sodium salt of formula Ihas an X-ray powder diffractogram substantially in accordance with thatshown in FIG. 7.

In another embodiment, the polymorph II of the sodium salt of formula Ihas an infrared spectrum substantially in accordance with that shown inFIG. 6.

In another embodiment, the polymorph II of the sodium salt of formula Ihas an X-ray powder diffractogram substantially in accordance with thatshown in FIG. 7 and an infrared spectrum substantially in accordancewith that shown in FIG. 6.

The present invention further provides a pharmaceutical compositionwhich comprises the sodium salt of formula I in any of its forms and oneor more pharmaceutically acceptable excipients. In a preferredembodiment, the pharmaceutical composition is adapted for oraladministration.

The present invention further provides the use of the sodium salt offormula I in any of its forms for the manufacture of a medicament forthe treatment or prevention of inflammatory bowel disease, includingulcerative colitis and Crohn's disease.

The present invention also relates to the use of the sodium salt offormula I in any of its forms for the treatment or prevention ofinflammatory bowel disease, including ulcerative colitis and Crohn'sdisease.

The present invention further relates to the sodium salt of formula I inany of its forms for use in therapy, and particularly for the treatmentor prevention of inflammatory bowel disease, including ulcerativecolitis and Crohn's disease.

The present invention further relates to a method of treating orpreventing inflammatory bowel disease, including ulcerative colitis andCrohn's disease, in a mammal in need thereof, specially a human being,which comprises administering to said mammal a therapeutically effectiveamount of the sodium salt of formula I in any of its forms.

The sodium salt of formula I can be obtained by any conventionalprocedure for preparing salts. For example, it can be prepared from(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid by treatment with one equivalent of sodium hydroxide in a suitablesolvent. As examples of suitable solvents we can mention ethanol andmethanol.

The sodium salt of formula I is obtained as an amorphous solid from asolution of said sodium salt of UR-12746, either by evaporation of thesolvent or by precipitation, for example by the addition over a secondmore apolar solvent, as explained in more detail in example 1.

The sodium salt of formula I is obtained in crystalline form bycrystallization of a solution of the sodium salt of UR-12746 in asuitable solvent or solvents. Depending on the conditions under whichthe crystallization is carried out, the sodium salt of formula I isobtained as polymorph I or polymorph II.

The source solution of sodium salt of UR-12746 to carry out thecrystallization can be obtained either by treatment of UR-12746 withsodium hydroxide, as mentioned above, or can be prepared from sodiumsalt of UR-12746 previously obtained.

To obtain polymorph 1, crystallization is preferably carried out usingethanol as the solvent. We have found that the product crystallizes wellfrom a solution in ethanol at a crystallization temperature in the range20-70° C. Preferably, the solution contains a concentration of sodiumsalt of UR-12746 (expressed as mL solvent/g of UR-12746 used as startingmaterial) in the range 1.9-6.0 mL/g and must contain the lowest possibleamount of water, in any case below 4% w/w. The preparation of polymorphI of the sodium salt of UR-12746 is explained in greater detail inexample 2.

Polymorph II is preferably obtained from mixtures of ethanol or methanolwith a second more apolar solvent such as ethyl acetate, acetonitrile orheptane and optionally in the presence of a small amount of water. Forexample, we have found that polymorph II crystallizes well in a mixtureof ethanol-ethyl acetate- water. Preferably, the solution contains aconcentration of sodium salt of UR- 12746 (given as mL solvent/gstarting material (i.e. UR-12746 or UR-12746 sodium salt) expressed as gUR-12746) of 2.8-6.6 mL ethanol/g, 5.4-15 mL ethyl acetate/g and0.13-0.33 mL water/g and crystallization is carried out at a temperaturein the range between 25 and 70° C. The preparation of polymorph II ofthe sodium salt of UR-12746 is explained in greater detail in examples 3and 4.

As will be obvious to those skilled in the art, crystallization can bestimulated, if desired, by seeding the solution with purepreviously-obtained seed crystals of the crystalline form that it isdesired to obtain.

Polymorph I and polymorph II exhibit significantly different X-raypowder diffractograms and infrared spectra and thus can be distinguishedusing any of these two techniques. X-ray powder diffractogramsrepresentative of polymorph I and polymorph II are shown in FIGS. 5 and7, respectively, whereas representative infrared spectra are shown inFIGS. 4 and 6.

The region of the X-ray powder diffractograms that is more useful todistinguish polymorph I and polymorph II is the region occurring between16.5° and 18° (angle 2θ). Polymorph I exhibits a strong peak at 16.90°,not present in polymorph II, whereas the latter exhibits a strong peakat 17.77°, not present in polymorph I.

In case infrared spectroscopy is used to distinguish the two polymorphs,the regions of the spectra that are more useful to distinguish the twopolymorphs are between 800 and 900 cm⁻¹ and between 550 and 650 cm⁻¹.

DSC, on the contrary, is not a suitable method to distinguish the twopolymorphs because they exhibit very similar melting points.

As will be obvious to those skilled in the art, the values of the angle2θ in the X-ray powder diffractograms as well as the relative intensityof the peaks may vary depending on the particular instrument used aswell as on the preparation of the sample. For this reason, the 2θ valuesmentioned to describe polymorphs I and II should not be considered asabsolute values but may vary by ±0.2° .

The sodium salt of UR-12746 that is the object of the present inventionis useful, as mentioned above, for the treatment or prevention ofinflammatory bowel disease in mammals, including man. The compound ofthe present invention is preferably administered orally, although it canalso be adapted to other modes of administration, particularly rectaladministration.

The present invention also relates to the pharmaceutical compositionswhich comprise the compound of the present invention and one or moreexcipients or other auxiliary agents if necessary. Said compositions canbe analogous to those described for UR-12746 in patent application WO97/09329, which is herein incorporated as reference, and can be preparedfollowing standard pharmaceutical formulation techniques.

Solid compositions for oral administration include tablets, dispersiblepowders, granules and capsules. In tablets, the active component isadmixed with at least one inert diluent such as lactose, starch,mannitol or calcium phosphate; binding agents for example corn starch,gelatine, microcrystalline cellulose or polyvinylpyrrolidone; andlubricating agents for example magnesium stearate, stearic acid or talc.The tablets may be coated according to methods well known in normalpharmaceutical practice. Formulations for oral use also include capsulesof absorbable material, such as gelatin, containing the activeingredient with or without the addition of inert solid diluents or otherexcipients.

Oral compositions may also be presented as dispersible powders andgranules suitable for the preparation of a suspension by the addition ofwater or other suitable vehicle. These preparations comprise the activeingredient and excipients such as dispersing or wetting agents,suspending agents, such as sodium carboxymethylcellulose,methylcellulose, hydroxypropylmethylcellulose, sodium alginate,polyvinylpyrrolidone, gum tragacanth, xantham gum, gum acacia, andpreservatives, such as methyl or propyl p-hydroxybenzoate. Additionalexcipients, for example sweetening, flavouring and colouring agents mayalso be present.

Liquid compositions for oral administration include emulsions,solutions, suspensions, syrups and elixirs containing commonly usedinert diluents, such as distilled water, ethanol, sorbitol, glycerol, orpropylene glycol. Such compositions may also comprise conventionaladditives such as wetting agents, suspending agents, sweetening,flavouring, preserving agents and buffers.

The compound of the invention may also be administered rectally, forexample in the form of suppositories or enemas, which include aqueous oroily solutions as well as suspensions and emulsions. Such compositionsare prepared following standard procedures, well known by those skilledin the art. For example, suppositories can be prepared by mixing theactive ingredient with a conventional suppository base such as cocoabutter or other glycerides.

The dosage and frequency of dose may vary depending upon several factorsincluding symptoms, age and body weight of the patient. In general, thecompound of the invention may be administered orally or rectally tohuman patients at a daily dosage of from about 500 to about 10000 mg foran adult, which may be administered either as a single dose or asdivided doses. However, in special cases and at the discretion of theattending physician, doses outside this margin may be required.

The following examples illustrate, but do not limit, the scope of thepresent invention. Instruments that have been used:

infrared spectra were recorded in KBr discs using a spectrophotometerPerkin Elmer 983 (examples 1 and 2) or Bomen MB-100 (example 3);

DSC spectra were recorded using a Mettler TA-3000 apparatus and a DSC-20coupled to a computer system equipped with the Mettler Toledo STAR^(e)System software;

X-ray powder diffractograms were recorded by means of a PhilipsXpert-MPD automated powder diffractometer-and using a radiation sourceof Cu Kα(λ=1.542 Å).

EXAMPLE 1 Preparation of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid in amorphous form

107 mg of NaOH was dissolved in 67 mL of boiling methanol. 1.7 g of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidi-nyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid (obtained according to the method described in patent applicationWO 97/09329) was added, and the mixture was further heated for 10 min.The mixture was filtered while still hot, concentrated to a volume of 5mL and the resulting solution was added dropwise to ethyl acetate (30mL) at room temperature and under stirring, to yield a fine yellowsolid. This solid was filtered and dried in vacuo at 70° C., to give 1.5g of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid in amorphous form.

The product obtained exhibits a flat DSC diagram that is characteristicof amorphous products, with a small heat absorption at about 260° C. Arepresentative infrared spectrum of this product is shown in FIG. 1. Bymeans of X-ray powder diffraction, the compound was shown to beamorphous; its corresponding diffractogram is shown in FIG. 2.

EXAMPLE 2 Preparation of polymorph I of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid

To a suspension of 100.0 g of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]-phenyl]azo]benzoicacid (93.3% assay) in 1.5 L of absolute ethanol, 6.58 g of sodiumhydroxide was added and the mixture was stirred at 60-65° C. tilldissolution. The resulting solution was filtered and concentrated bydistillation in vacuo to a volume of 200-300 mL. This concentratedsolution was stirred at 55-65° C. for about 4 hours, giving rise to anabundant precipitate. Heating was stopped and the mixture was furtherstirred at room temperature (18-22° C.) for about 16-20 hours. Theproduct was centrifuged, washed in the centrifuge with absolute ethanol(2×10 mL) and dried in vacuo at 80° C. 85-87 g of the polymorph I of thesodium salt of (Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-il)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid was obtained.

A representative DSC diagram of polymorph I is shown in FIG. 3. Theproduct exhibits a DSC melting peak usually in the range 263-267° C. Arepresentative infrared spectrum of polymorph I is shown in FIG. 4. Arepresentative X-ray powder diffractogram of polymorph I is shown inFIG. 5. The values of angle 2θ (in degrees), spacing “d” (in Angstroms)and relative intensity (%) of said X-ray diffractogram are shown inTable 1 in numerical form for the peaks having a relative intensityequal or higher than 10%.

TABLE 1 Angle 2θ d Relat. Int. (°) (Å) (%) 6.035 14.645 74 6.375 13.86536 8.010 11.038 15 8.535 10.360 18 11.725 7.548 16 13.180 6.718 2213.650 6.487 17 14.545 6.090 19 14.970 5.918 15 16.080 5.512 26 16.8955.248 100 17.225 5.148 35 17.580 5.045 11 18.200 4.874 14 18.445 4.81015 19.095 4.648 71 19.530 4.545 46 20.145 4.408 39 21.115 4.208 6121.430 4.146 37 21.565 4.121 41 21.855 4.067 40 22.480 3.955 40 23.7103.753 32 24.060 3.699 44 24.230 3.673 41 25.140 3.542 18 25.535 3.488 1726.065 3.419 12 27.400 3.255 16 27.905 3.197 10 28.330 3.150 16 30.8152.902 14 32.880 2.724 11

EXAMPLE 3 Preparation of polymorph II of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-4-[(2-methyl-1H-imidazo[4,5-c]pyridin1-yl)methyl]-1-piperidinyl]-3oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid from polymorph I of the sodium salt of UR-12746

41 g of the polymorph I of the sodium salt of UR-12746 was dissolved in160 mL of absolute ethanol and 11 mL of water, at 60-65° C. To thissolution, 500 mL of ethyl acetate was added slowly, keeping thetemperature at 65-70° C. The solution was cooled down to roomtemperature over 2 hours, whereby the product crystallized, and wasfurther cooled in an ice bath for 2 more hours. The product wascentrifuged and dried in vacuo at 80° C., yielding 30 g of polymorph II.

A representative DSC diagram of polymorph II is shown in FIG. 8. Theproduct exhibits a DSC melting peak usually in the range 264-275° C. Arepresentative infrared spectrum of polymorph II is shown in FIG. 6. Arepresentative X-ray powder diffractogram of polymorph II is shown inFIG. 7.

The values of angle 2θ (in degrees), spacing “d”(in Angstroms) andrelative intensity (%) of said X-ray diffractogram are shown in Table 2in numerical form for the peaks having a relative intensity equal orhigher than 10%.

TABLE 2 Angle 2θ d Relat. Int. (°) (Å) (%) 6.065 14.573 27 8.295 10.65923 8.820 10.026 28 11.710 7.557 63 12.520 7.070 29 13.235 6.690 5513.400 6.608 34 13.695 6.466 15 15.155 5.846 11 15.715 5.639 86 17.1655.166 15 17.770 4.991 51 18.955 4.682 100 19.670 4.513 23 20.330 4.36892 20.835 4.264 43 21.390 4.154 54 21.710 4.094 46 22.080 4.026 2922.770 3.905 41 22.965 3.873 39 23.495 3.787 50 23.950 3.716 59 24.2703.667 19 25.060 3.553 31 25.605 3.479 21 26.230 3.398 24 26.640 3.346 2527.135 3.286 27 27.960 3.191 13 28.495 3.132 12 28.960 3.083 23 29.5003.028 31 29.895 2.989 13 30.480 2.933 14 31.725 2.821 12 32.220 2.778 1333.400 2.683 11 40.720 2.216 11

EXAMPLE 4 Preparation of polymorph II of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid from UR-12746

14.80 g of UR-12746 and 0.96 g of sodium hydroxide was dissolved in 225mL of ethanol containing 3.15% (w/w) of water. The mixture was heated at45-50° C. until dissolution and was then filtered. The filtrate wasconcentrated in vacuo, distilling off about 180 mL of ethanol from thesolution. To the concentrated solution 2 mL of water was added, and theresulting solution was heated at 65° C. At 60-65° C. 80 mL of ethylacetate was added slowly and in portions. The resulting solution wascooled down to room temperature over 3 hours, whereby the productcrystallized. The product obtained was centrifuged and dried in vacuo at80° C., yielding 4.75 g of polymorph II.

EXAMPLE 5 Comparative study of the azoreduction of UR-12746 and thesodium salt of UR-12746 after oral administration

As mentioned above, UR-12746 is a compound designed to be metabolized inthe colon by the intestinal bacteria to deliver 5-ASA and an amine withPAF antagonist activity, UR-12715.

The level of azoreduction has been studied by determining thedistribution of UR-12746 and UR-12715 in faeces after the oraladministration of UR-12746 and its sodium salt in rats and monkeys.

i) Study in rats

For the study in rats, 6 female Sprague-Dawley rats weighing between 169and 185 g were used. UR-12746 and the sodium salt of UR-12746 (polymorphI) were orally administered to three rats each as a suspension in 0.2%carboxymethylcelulose (CMC), at a dose of 50 mg/kg (100 mg of testcompound/10 mL of 0.2% CMC).

The rats were placed in metabolic cages, so that urine and faeces couldbe separately collected, and faeces were collected during the periods0-24 h and 24-48 h. The faeces collected in the same period wereweighted and crumbled. Water was added (2 mL of water/g of faeces) andthe paste obtained was stirred to homogeneity. The total weight of thehomogenate was then determined.

An aliquot of this homogenate (about 2 g) was mixed with 4 mL of MeOH,stirred in a Vortex and centrifuged for 10 minutes at 4500 rpm (3000 g).The supernatant was filtered through a 0.45 μm filter, and theconcentrations of the administered product and metabolite present in thesample were determined by a HPLC chromatographic method with gradientelution and ultraviolet detection, under the conditions detailed below:

Column: Hypersil—Elite C18 5 μm (4.6 x 150 mm) Eluent: Pump A:Acetonitrile-Methanol (25:75) Pump B: Phosphate buffer, 25 mM pH: 7.50.54 g KH₂PO₄ 3.74 g Na₂HPO₄.2H₂O in 1 liter of water Gradient table:Time Pump A Pump B Flow Start 30 70 1 ml/min  1 minute 30 70 1 ml/min 26minutes 80 20 1 ml/min 30 minutes 80 20 1 ml/min 32 minutes 30 70 1ml/min 42 minutes 30 70 1 ml/min Injection vol.: 50 μL Detection: U.V.,λ: 210 nm Retention times: UR-12746: 24.2 min; UR-12715: 20.1 min(approx.)

The level of azoreduction was determined from the amounts of product andUR-12715 recovered in faeces. The relative percentage of the amountscorresponding to the product (UR-12746 or sodium salt of UR-12746) andto the metabolite (UR-12715) found in faeces after oral administrationare shown in Table 3. Results are given as the mean values.

TABLE 3 Sodium salt UR-12746 of UR-12746 Product UR-12715 ProductUR-12715  0-24 h 78.8% 21.2% 21.1% 78.9% 24-48 h 52.5% 47.5% 12.1% 87.9% 0-48 h 76.1% 23.9% 20.8% 79.2%

Similar results were obtained when the sodium salt of UR-12746 inamorphous form was used.

ii) Study in monkeys

6 Cynomolgus monkeys were used for this study. Each test product wasadministered to three monkeys, respectively. UR-12746 was administeredas a suspension in 0.2% CMC, at a dose of 100 mg/kg p.o. (1000 mgUR-12746/10 mL of 0.2% CMC), whereas the sodium salt of UR-12746(polymorph I) was administered as individualized capsules for eachanimal at a dose of 100 mg/kg p.o.

The monkeys were placed in metabolic cages, so that urine and faecescould be separately collected, and faeces corresponding to the periods0-24 h, 24-48 h and 48-72 h were collected.

The treatment of the faeces and the determination of the amount ofadministered product and metabolite present in the samples were carriedout following the same procedure described above for the study in rats.

As in the rat study, the azoreduction level was determined from theamounts of product and UR-12715 recovered in faeces. The resultsobtained are shown in Table 4:

TABLE 4 Sodium salt UR-12746 of UR-12746 Product UR-12715 ProductUR-12715  0-24 h >99% 0% 12.6% 87.4% 24-48 h >99% 0%  6.5% 93.5% 48-72h >99% 0%  5.0% 95.0%  0-72 h >99% 0%  9.7% 90.3%

The results of these studies clearly show that the sodium salt ofUR-12746 is metabolized in the colon to a much greater extent thanUR-12746. Thus, whereas just 24% of azoreduction takes place after oraladministration of UR- 12746 in rats, a much higher azoreduction, around79%, is observed when the sodium salt of UR-12746 is administered. Thisdifferent behaviour is still more clearly observed in monkeys, where noazoreduction is observed after administration of UR-12746 while a veryhigh level of metabolization in the colon (around 90%) is observed whenthe sodium salt of UR-12746 is administered. The sodium salt of UR-12746is therefore a more suitable compound to be used for the treatment orprevention of inflammatory bowel disease.

What is claimed is:
 1. Sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1piperdinyl]-3-oxo-1-phenyl-1propenyl]phenyl]phenyl]azo]benzoic acid of formula I:


2. A compound according to claim 1, in amorphous form.
 3. A compoundaccording to claim 1, in crystalline form.
 4. A compound according toclaim 3, having an X-ray powder diffractogram, obtained at λ=1.542 Å andusing a radiation source of Cu Kα, comprising peaks at an angle 20 of6.04, 6.38, 8.01, 8.54, 11.73, 13.18, 13.65, 14.55, 14.97, 16.08, 16.90,17.23, 19.10, 19.53, 20.15, 21.12, 21.86, 22.48, 23.71, and 24.23°±0.2°.5. A compound according to claim 3, having an X-ray powder diffractogramsubstantially in accordance with that shown in FIG.
 5. 6. A compoundaccording to claim 3, having an infrared spectrum substantially inaccordance with that shown in FIG.
 34. 7. A compound according to claim3, having an X-ray powder diffractogram substatially in accordance withthat shown in FIG. 5 and an infrared spectrum substantially inaccordance with that shown in FIG.
 4. 8. A compound according to claim3, having an X-ray powder diffractogram, obtained at λ=1.542 Å and usinga radiation source of Cu Kα, comprising peaks at an angle 20 of 6.07,8.30, 8.82, 11.71, 12.52, 13.24, 15.72, 17.77, 18.96, 19.67, 20.33,20.84, 21.39, 21.71, 22.77, 22.97, 23.50, 23.95 and 29.50°±0.2°.
 9. Acompound according to claim 3, having an X-ray powder diffractogramsubstantially in accordance with that shown in FIG.
 7. 10. A compoundaccording to claim 3, having an infrared spectrum substantially inaccordance with that shown in FIG.
 6. 11. A compound according to claim3, having an X-ray powder diffractogram substantially in accordance withthat shown in FIG. 7 and an infrared spectrum substantially inaaccordance with that shown in FIG.
 6. 12. A method of manufacturing amedicament for the treatment or prevention of inflammatory boweldisease, the method comprising incorporating an amount of the compoundaccording to claim 1, effective to treat inflammatory bowel disease intothe medicament.
 13. A method of manfacturing a medicament for thetreatment or prevention of inflammatory bowel disease, the methodcomprising incorporating an amount of the compound according to claim 2,effective to treat inflammatory bowel disease into the medicament.
 14. Amethod of manufacturing a medicament for the treatment or prevention ofinflammatory bowel disease, the method comprising incorporating anamount of the compound according to claim 3, effective to treatinflammatory bowel.
 15. A process for preparing a compound according toclaim 1, the process comprising treating(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid with one equivalent of sodium hydroxide in a suitable solvent. 16.A process according to claim 15, wherein the solvent is ethanol ormethanol.
 17. A process for preparing a compound according to claim 2,the process comprising obtaining the compound from a solution of thesolution salt of(Z)-2-hydroxy-5-[[-4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid either by evaporating the solvent or by precipitation by theaddition over a second more apolar solvent.
 18. A process for preparinga compound according to claim 3, the process comprising crystallizationa solution of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1-H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperdinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid in a suitable solvent of solvents.
 19. A process according to claim18, wherein the source solution of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-4-[(2methyl-1H-imidazo[4,5-c]pyridin-1yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]-phenyl]azo]benzoicacid is prepared by treatment of(Z)-2-hydroxy-5-[[4-[3-[4-](2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl1-propenyl]phenyl]azo]benzoicacid with one equivalent of sodium hydroxide in a suitable solvent orsolvents.
 20. A process according to claim 18, wherein the sourcesolution of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid is prepared from sodium salt of(Z)-2-hydroxy-5-[[4-3-[4[(2-methyl-1H-imidazo[4,5-c]pyridin-1yl)methyl]-1-piperdinyl]-3-oxo-1-phenyl]phenyl]azo]benzoicacid previously obtained.
 21. A process for preparing a compoundaccording to claim 4, the process comprising crystallizing a solution ofthe sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid in ethanol.
 22. A process according to claim 21, wherein thecrystallization is carried out at a temperature in the range 20-70° C.23. A process according to claim 21, wherein the solution contains aconcentration of sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid (expressed as mL solvent/g of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid used as starting material) in the range 1.9-6.0 mL/g.
 24. A processaccording to claim 21, wherein the solution contains less than 4% w/w ofwater.
 25. A process according to claim 22, wherein the solutioncontains a concentration of sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid (expressed as mL solvent/g of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid used as starting material) in the range 1.9-6.0 mL/g.
 26. A processaccording to claim 22, wherein the solution contains less than 4% w/w ofwater.
 27. A process according to claim 23, wherein the solution lessthan 4% w/w of the water.
 28. A process according to claim 21, whereinthe solution conatins less than 0.4% w/w of water, the crystallizationis carried out at a temperature in the range of 20°-70° and wherein thesolution contains a concentration of sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid (expressed as mL solvent/g of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid used as starting material) in the range 1.9-6.0 mL/g.
 29. A processfor preparing a compound according to claim 5, the process comprisingcrystallizing a solution of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid in ethanol.
 30. A process for preparing a compound according toclaim 6, the process comprising crystallizing a solution of the sodiumsalt of(Z)-2-hydroxy-5-[[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]azo]benzoicacid in ethanol.
 31. A process for preparing a compound according toclaim 7, the process comprising crystallizing a solution of the sodiumsalt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazol[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid in ethanol.
 32. A process for preparing a compound according toclaim 8, the process comprising crystallizing a solution of the sodiumsalt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid in mixtures of ethanol or methanol with a second more apolarsolvent, and optionally in the presence of a small amount of water. 33.A process according to claim 32, wherein the second more apolar solventis ethyl acetate, acetonitrile or heptane.
 34. A process according toclaim 33, wherein the second more apolar solvent is ethyl acetate.
 35. Aprocess according to claim 32, wherein crystallization is carried out ina mixture of ethanol-ethyl acetate-water.
 36. A process according toclaim 35, wherein the crystallization is carried out at a temperature inthe range between 25 and 70° C.
 37. A process according to claim 35,wherein the solution contains a concentration of sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid (given as mL solvent/g starting material expressed as g of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid) of 2.8-6.6 mL ethanol/g, 5.4-15 mL ethyl acetate/g and 0.13-0.33mL water/g.
 38. A process according to claim 36, wherein the solutioncontains a concentration of sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid (given as mL solvent/g starting material expressed as g of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid) of 2.8-6.6 mL ethanol/g, 5.4-15 mL ethyl acetate/g and 0.13-0.33mL water/g.
 39. A process for preparing a compound according to claim 9,the process comprising crystallizing a solution of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid in mixtures of ethanol or methanol with a second more apolarsolvent, and optionally in the presence of a small amount of water. 40.A process for preparing a compound according to claim 10, the processcomprising crystallizing a solution of the sodium salt of(Z)-2-hydroxy-5[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid in mixture of ethanol or methanol with a second more apolarsolvent, and optionally in the presence of a small amount of water. 41.A process for preparing a compound according to claim 11, the processcomprising crystallizing a solution of the sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4[(2-methyl-1H-imadazo[4,5-c]pyridin-1-yl)methyl]-1-piperidinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid in mixtures of ethanol or methanol with a second more apolarsolvent, and optionally in the presence of a small amount of water. 42.A pharmaceutical composition that comprises an effective amount of asodium salt of(Z)-2-hydroxy-5[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1yl)methyl-1-piperidinyl]-3-oxo-1phenyl-1-propenyl]-phenyl]azo]benzoicacid of formula I:

and one or more pharmaceutically acceptable excipients.
 43. Thecomposition of claim 42, wherein the salt is in amorphous form.
 44. Thecomposition of claim 42, wherein the salt is in crystalline form.
 45. Amethod of treating or preventing inflammatory bowel disease, the methodcomprising administering an amount of a sodium salt of(Z)-2-hydroxy-5-[[4-[3-[4-[(2-methyl-1H-imidazo[4,5-c]pyridin-1-yl)methyl]-1-piperdinyl]-3-oxo-1-phenyl-1-propenyl]phenyl]azo]benzoicacid of formula I:

effective to treat inflammatory bowel disease to a mammal in needtherof.
 46. The method of claim 45, wherein the mammal is a human. 47.The method of claim 45, wherein the inflammatory bowel disease isulcerative colitis.
 48. The method of claim 45, wherein the inflammatorybowel disease is Crohn's disease.
 49. The method of claim 45, whereinthe salt is in amorphous form.
 50. The method of claim 45, wherein thesalt is in crystalline form.
 51. The method of claim 49, wherein theinflammatory bowel disease is ulcerative colitis.
 52. The method ofclaim 49, wherein the inflammatory bowel disease is Crohn's disease. 53.The method of claim 50, wherein the inflammatory bowel disease isulcerative colitis.
 54. The method of claim 50, wherein the inflammatorybowel disease is Crohn's disease.